British Airways is investigating the theft of customer data from its website and mobile app.

In a statement, the airline said that between August 21 and September 5 the personal and financial details of customers making bookings on their website and their app were compromised.

The breach has now been resolved but BA have notified the authorities and continue to investigate.

British Airways is investigating the theft of customer data (Image: PA)

It also said that they are communicating with affected customers and advise those who believe they may have been affected to contact their banks or credit card providers and follow their recommended advice.

Alex Cruz, British Airways’ chairman and chief executive said: “We are deeply sorry for the disruption that this criminal activity has caused.

"We take the protection of our customers’ data very seriously.”

The airline says the stolen data did not include travel or passport details.